Tunneling-machine.



E. S. MCKINL'AY.

TUNNELING MACHINE.

APPUCATON FILED OCT' 29,1910- RENEWED APR- 6 1918: 1,284,398. PatentedNov. 12,1918.

4 SHEETS-SHEET I.

E. S. IVCKINLAY.

TUNNELING MACHINE.

APPLICATION FILED 00129, 1910. III-:NEwED APR. 6, IsIa.

Patent-ed Nov. 12, 1918.

4 SHEETS-SHEET 3.

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n #//MMMM E. S. lVIcKINLAY.

TUNNELING MACHINE.

APPLICATION FILED OCT. 29, i910. RENEWED APR. 6, 19H?.

' Patented Nov. 12, 1918.

4 SHEETS-SHEET 4.

wit/naman t; a# cierra EDWARD S. MOKINLY, 0F OAK CREEK, COLORADO.

TUN N ELING-MACHINE.

Specification of Letters Patent.

Patented Nov. l2, i918.

Application filed October 29, 1910, Serial No. 589,807. Renewed April G,1918. Serial No. 227,132.

To all whom t may concern.'

Be it known that I, EDWARD S. MCKIN- LAY, a native-born citizen of theUnited States, residing at Oak Creek, in the county of Routt and Stateof Colorado, have invented certain new and useful Improvements inTunneling-Machines, of which the following is. a specification,reference being had therein to the accompanying drawing.

This invention relates to improvements in tunneling machines and isespecially adapted for rock work. With certain modiiications, however,it is adapted to be used in driving entries in coal mines and for othersimilar urposes. l

One o ject of theinvention is to provide a light, easily moved machinewith improved supporting means. Another object is to provide improvedmeans for rotating the cutter head. A further object is to provide meansfor softening and cracking the rock at points adjacent tothe cuttingtools. Still further objects are -to provide improved feeding means,improved means for advancing the supporting parts, and improved meansfor carrying the loosened material backward away from the cutter-head.Other objects will be 'apparent from the following specification andclaims. l

In the accompanying drawings forming a part of this application l haveshown, for the purpose of illustration, oneform of mechanism embodyingmy invention. lt

`will be understood however that many changes and modifications may bemade in the construction shown without departing from the spirit of myinvention.

Of the drawings,

Figure l is a cross sectional elevation showing the machine in operativeposition in a tunnel, a part of the mechanism is broken away in order tomore clearly show the construction.

Fig. 2 is an enlarged detail view showing partly in cross section theconstruction of one of the radial arms and attached mers.

Fig. 3 is a fragmentary plan View shewing an arm at right angles to thearm shown in Fig. 2.

Fig. 4 is a cross sectional view taken along the line 1*4 of Fig. 1.

Fig. 5 is a. fragmentary cross sectional detail view of the advancesupplemental cutter and adjacent bearing.

Fig. 6 is an end View of the supplementary cutter.

Fig.- 7 is a fragmentary cross sectional view taken along the line 7 7of Fig. l, showing one of the elevating scoops.

Fig. 8 is a detail view showing one of the pipe connections.

Referring to the drawings, l represents the main supporting tube uponwhich the other parts of the machine are mounted. As shown in Fig. 2,this tube comprises in the present form of mechanism, two sep arateparts l@ and lb. It will be understood, however, that if preferred thesetwo parts may be made integral. 2 represents a central connectingcasting or hub to which are secured the adjacent ends of the tube partsla and l". The hub 2 is hollow and the chamber 3 within it communicates:freely lwith the interior of the tube part 1b. rl`he chamber 3 howeveris separated from the interior of the tube part 1a by means of a wall 4.

The tube 1 is supported in two bearings 5 and 6. The rear bearing 6 ispivotally secured by means of trunnions 7, 7, and brackets 8 to theframe 9 which comprises two parallel vertical side bars l0, l0 carryingthe brackets 8, 8, and horizontal cross bars 1l, l1, at the ends of theside bars. Screw jacks l2, 12, are secured to the horizontal cross barsand may be adjusted to engage with the top and bottom oi' the tunnel. lnthis way the frame 9 is secured in positicn but is at the same timeadapted for rapid adieustment or for ready release when it is desired tomove it. p

The forward end 0f the tube l is provided with a series of cutters 13,which are suitably arranged to cut a circular holein the Aiorward faceof the tunnel opening.

'l'he forward end of the tube is Open and the material which is loosenedb v the cutters 13 will enter its open end where it will be engaged by ahelical rib l-t termed on the inner surface of the tube. rl`his helicalrib serves as a spiral conveyer to carry materials backward as the tubeis rotated. Holes 15, 15, are provided in the tube from which thematerial mav be discharged. ward bearing ,.3 is provided with an outernon-rotating' casing ltwhich is secured against relative longitudinalmovement by collars 1T and .1S on the tube 1. Vithin the casing 1U islocated a series of rollers 19 which are adapted to bear against theouter .surface of the. Jtube and against the inner surface of theeasing. As the machine is advanced the bearing casing 16 enters theaperture formed by the cutters 13 and is held against rotation b vfrictional engagement with the sides ot the opening. lt thusl serves asa bearing box in which the rollers 19 operate.

rlhe main cutter-head is indicated as a whole by 20. rilhis cutter headpreferably comprises a series of radial arms. 1n the drawings forpurposes of illustration, I have shown four of these arms located atright angles to each other and designated QQ. QQ, and 23, Q3. lt will beunderstood. however, that other numbers of arms, such as six or eight,may be used if deemed desirable.

l. at present, prefer to construct the arms Q2. QQ. and '28, of pipes,the inner ends of which are screwed or otherwise secured to the cent-ralhub. For reasons which will be fully explained hereinafter, each of thefour radial arms is composed of two separate telescoping sections suchas are indicated in Fig. Q, by Qi and rlhe section which is secured tothe hub is preferably the larger and communicates at its inner end withthe chamber The section 2i is slidable within the section 25 and isclosed at its outer end by means of a cap Q6. The section 25 ispreferably provided with an internal key-way which is engaged by a keyQT secured to the pipe section 2i. This key and key-way prevents rotarymovement of the section 2t relative to the section 25. A split clam) QSis secured to the end of the section Q5 and frictionally engages thesection Qt. This clamp may be tightened by means of a screw 29. l havedescribed in detail but one of the. radial arms, but it will beunderstood that the foregoing description is equally applicable to allot the arms es. es, es.

vliach alternate radial arm (in this case 22. carries a plurality ofapproximately equally spaced cutting" or rock engaging tools which are jably of the reciprocatory type and whi Y. may be operated by rThe forjcompressed air, although if desired other mediums, such as steam may beused. ln the drawings for the purposes of illustration, l haveshownthree of these tools on each arm 22, one of which 30, is secured tothe inner section 25, and two of which 3l and 3Q are secured to theouter section 24. yhe tool 30 is formed with a bracket 33 which embracesthe section-'25 and may be frictionally clamped against it by means of abolt 34. The tools 31 and 3Q are also formed in similar brackets 35 and36 which similarly engage the .section 24. By this means the tools areadjustably secured to the arms so that they may be moved not onlyradially but also angularly relatively to the plane ofthe cutter-headand rela tively to the lines of rotary movement. On each arm between thearms carrying the tools 30, 31 and 32, (in this case 23, 23) are locatedother reciprocatory rock engaging air operated tools 37, 38 and 39,preferably somewhat larger and hea-vier than the tools 30, 31 and Theyare secured to the arms 23 by means of clamping brackets similar tothose previously described and by means of which they can be angularlyand radially adjusted. lt will be noted that the tools ST'and 38 aresecured to the section Q5 and that the tool 39 is secured to the section2i. 1t will be noted from a reference to the drawings that the tools 30,31 and 32 are adjusted and located for the cutting7 as the cutter-headis rotated, of three approximately equally spaced annular grooves 40, 41and 42. rEhe tools 37, 38 and 39 are positioned to strike the ridgesformed between the grooves and between the inner grooves and thecircular aperture cut. by the, tools 13. The function of these heaviertools 3T, 3S and 39 is therefore to crack and break down the coal orrock left between the grooves cut by the other tools. j

lt will also be noted that each of the tools is positioned at an acuteangle to the for ward face of the tunnel so that oblique blows arestruck. T he re-action from these angular blows serves to rotate themachine. The speed and powerof rotation may be regulated by adjustingthe angularity of the hammers. j

lt is to be noted that the machine may be adjusted for cutting a tunnelof any desired diameter. This is accomplished by changing the positionof the telescoping arm sections Qsi. After the sections have beenproperly located, further adjustment of the hammers may be had by meansof the brackets on which they are mounted.

fis an additional means for rotating the machine l provide supplementalreciprocatory cutting tools d3. 43, at the outer ends of some of thearms. ln this ease 'they are shown at the ends of the arms "227 and aresecured to suitable brackets formed on the caps 26. These tools 43, 43,are adapted to strike blows at acute angles relative to their lines ofrotary movement and therefore to strike the circular surface of thetunnel with oblique blows the re-action from which aids in giving rotarymotion to the cutter-head.

From the foregoing description it. will be seen that for rotating thelapparatus I make use of all of the cutting tools, namely,

at 30, 3l and 32, those at 37, 38 and 39, and

those at 43. Each of these tools is mounted to strike the Wall of thetunnel at an acute angle relative to the wallv and to the line of rotarymovement of the tool itself.` ln other words, each tool, whether actingon the flat forward face or on the cylindrical peripheral face, deliversblowsy at backward acute angles thus tending by the reaction to rotatethe cutter-head.

Any desired means may be used for supplying air to the cutting tools,but the means which l at present prefer, is shown in Fig. 2. As has beenpreviously stated the hub 2 is formed with a central chamber 3 whichcommunicates with the interior of the tube section l".

Each of the hollow arms 22, 22, and 23, 23, communicates at its innerend with this central chamber 3 in the hub 2. By supplying air underpressure through the tube section lb a pressure is maintained in all ofthe hollow arms. By means of flexible piping indicated by 44, 45, and46, air is led to the tools 31, 32 and 43. By means of the flexible pipe4T air 'is led to the tool 30 directly from the chamber 3. By a similarsystem of piping the tools 37, 38 and 39 are supplied with air.

Referring now to the means for advancing the cutter-head as the toolsoperate, 48 is a hollow cylinder secured to the bearing 6. The tube l isnot only rotatable in the bearing 6, but is also slidable there through.By reference to Fig. l, it will be noted that the tube 1 is somewhatsmaller in diameter than 'the interior of the cylinder 48 and that it isprovided with a head 49 adapted to engage the interior of the cylinder48. Adjacent the head 49 is a non-rotating piston 50 also slidable inthe cylinder 48. The head 49 and the piston 50 are provided with centralalined apertures 5l and 52 which establish communication between theinterior of the cylinder and the interior of the tube. iir pressure issupplied to the cylinder through a pipe 53. The pressure of the air inthe cylinder 48 is exerted against the piston 56 from which it istransmitted through vthe head 49 and the tube l to the cutter-head andserves to hold the cutting tools up to their work. The air presurc isalso transmitted through the apertures 5l and and through the tubesect-ion il to the chamber 3 5 0 has been forced to the end of itstravel in the cylinder 48, it then becomes necessary to advance thecylinder and the bearing 6. This is done by closing the valve 53 andrelieving the pressure within the piston 48 through a cock 56. Thejack-screws l2, l2, are loosened so that the whole rear end of themachine is free and then air is admitted to the space 55 by opening thevalve 54. The pressure ot' the space 55 then forces the bearing 6 withthe framework 9 and also the cylinder 48, to positions close to thecutterhead. lhen this has been done and the valve 54 has been closed,the acks 12, l2, are again tightened and when the valve 53'CL is openedthe machine is ready for operation as before.

ln order to remove the debris loosened by the various cutters, I providea conveyer preferably of the endless belt type and indicated as a wholeby 5T. As shown in the drawings this conveyer comprises two horizontalparallel side bars 58, 58, at the ends of which are mounted rollers ordrums 59 and 60, over which passes the endless belt 61. The side bars58, 58. are supported at their forward ends by depending arms 62, theupper ends of which are secured to a collar 63 which loosely engages thetube section l, and .is held against relative longitudinal movement bymeans of engagement at its forward side with the hub 2, and at its rearside with a collar 64. The rear ends of the side bars 58 are supportedby and slidably engage with depending brackets 65 mounted on thecylinder 48.

66 is a shaft parallel and above one of the side bars 58 and isrotatably mounted in suitable bearings. The shaft 66 is operativelyconnected with the 'drum 6() by means of skew gearing 6T.

An air motor indicated by 68 is secured to `one of the side bars l0 ofthe framework 9.

Air is led to this motor through the pipe 69. lower is transmitted fromthe motor to the shaft 66 b v means of the bevel gearing 70, thevertical shaft Tl. the bevel gear T2 and the bevel gear T3. The gear 73is adapted to permit th(` shaft 66 to-slide through it, engagement beinghad with the shaft by means of a key i4 which slides in a longitudinalkeyuvalv formed in the shaft.

.it the ends of some of the arms (in this case 23. 23) are providedscoops T5 which are providei'i with forward extensions 'T6 which. act.as scrapers to work material backward into the plane of action of thescoops. ks shown in Fig. i", the scoops are adapted to pick up materialfrom the bot-tom of the tunnel and as they are carried around todeposit. this material n the conveyer 57. A car 7T may be provided toreceive the material from the rear end of the conveyer.

For operation on certain classes of rock, I provide supplemental meansadapted to cooperate with the cutting tool and to soften anddisintegrate the rock. Broadly considered these supplemental devicescomprise means for heating the rock to a high temperature. I have foundthatlcertain classes of rock are very materially softened when subjectedto heat. It hasalso been found desirable in certain cases to rapidlycool the heated rock in order to break it up and disintegrate it. Thiscooling mav be preferably accomplished by a jet of Water, though in somecases under certain peculiar conditions a chemical such as a weak acidsolution may be used instead of pure Water. lVhen a chemical solution isused the effect is not only to break the rock on account of the stonecontraction, but the liquid also percolates through the interstices ofthe fractured rock and further destroys it by chemical reaction.

In the drawings I have shown for the purposes of illustration one formof apparatus for accomplishing the results above set forth. Thisapparatus comprises a means for directing against the rock burning gasessuch as hydrocarbon and oxygen or acetylene and oxygen. It will be foundpreferable however, in some cases to use electric apparatus forsupplying the heat. 'I he burners are indicated in the drawings by 78,one being provided in advance of ea ch 0f the cutting tools 30, 3l, and32, and secured to it by means ofa bracket 0r arm 79. 80 represents anozzle for supplying a jet of water or other cooling medium against therock at a point between the point of connection of the burner 78 and thecutting tool.

In the drawings have shown one means for supplying gases and liquids tothe burners and jets 78 and 80. In each of the arms are located threepipes 8l, 82 and 83. rllhese pipes are each made in two sections whichtelescopicaily'engage to permit adjustment of the section of the arm.The pipes 32 and 8B carry the gases and pass out through the cap andconnected by means of tiexible ipe Satto the burners. The gases ierburners on the tools l DU hrough pipes 35 the interior mi, 1, p) fr. lrva a stuiing box in the rear messes 81 is led to the youter nozzles bymeans of flexible tubing- 90. 'I he Water for the nozzle on the tool 30is led through a flexible tube 91 from the interior of the chamber 3.rIhe pipes 81 and 91 are supplied through a pipe 92 which extendsbackward through the opening between the tanks 86 and 87, throughapertures l and 52 and through end ot' the cylinder 4S. T his pipe ismade in two parts connected by a union 93 which permits the forward partto turn and the rear part to remain stationary.

In view of the foregoing description it is thought that further detailedreference to the operation will not be necessary. It may be well howeverto briefly call attention to certain advantageous features. First, itWill be noted that the machine is entirely selfcontained, and that n0cumbersome and eX- pensive supporting framework or trackway is used.vice is provided for giving rotary motion to the cutter-head, thismotion being obtained from the oblique blows of the hammers themselves.The machine is adjustable for various diameters of tunnels and a simplemeans is provided for feeding the machine forward and also for advancingthe rear bearings from time to time. The foregoing are some of the moreimportant advantages incident to my machine but others will be apparentfrom the following claims.

What I claim is:

l. In a tunneling machine, the combination of a cutting mechanism, rearsupports for the cutting mechanism with respectl to which the saidmechanism is bodily movable longitudinally, the said rear supportengaging the wallsl of the tunnel formed by the cutting mechanism andbeing provided with means arranged to permit pivotal movemeut about ahorizontal axis and about a vertical axis. and a forward support for thecutting mechanism bodily movable therewith and adapted to engagetheforward face of the tunnel, substantially as set forth.

2. In a tunneling machine, the combination of a. cutting mechanism, rearsupports for the cutting mechanism with respect to which the saidmechanism is bodily movable longitudinally. the said rear supportenaging the walls of the tunnel for d t' i echanism and bei",y

permit pi i And furthermore no separate de,

3. In a. tunneling machine, the combination of ay cutting` mechanism, asupport for the cutting mechanism in advance thereof and having anon-rotary part, a support for the cutting mechanism in the rear thereofwith respect to which it is bodily movable longitudinally, a frameprovided with means for pivotally engaging diametrically opposite wallsof the tunnel formed by the cutting mechanism, and a connection betweenthe said rear support and the said frame permitting relative pivotalmovement about an axis at right anglesy to the axis of pivotalengagement of the frame with the tunnel walls, substantially as setforth.

4. In a tunneling machine, the combination of a rotary cuttingmechanism, a

rotary shaft on which the cutting mechanism is mounted, two supportingbearings for the shaft, each having a non-rotary. part, one of thebearings being in advance of the cutting mechanism and the other of the'bearings with respect to whichthe shaftis longitudinally movable beingat the rear of the cutting mechanism, a supporting frame for the rearbearing, the said frame being adapted to pivotally engage the walls ofthe, tunnellformed bythe cutting mechanism at diametrically oppositepoints, and a connection between the said rear bearing and the saidsupporting frame adapted to permit relative pivotal movement about anaxis at right angles to the axis of pivotal engagement of the supportingframe with the tunnel walls, substantially as set forth.

5. In a tunneling machine, the combination of a rotary cuttingmechanism, a rotary shaft on which the cutting mechanism is mounted, twobearings for the shaft each having a non-rotary part, one of thebearings being in advance of the cutting mechanism and the other of thebearings with respect to which the shaft is longitudinally movable beingat the rear of the cutting mechanism, a supporting frame for the rearbearing, the said frame comprising two parallel bars, one on each sideof the bearing, and jack screws adapted to pivotally engage at oppositepoints the walls of the tunnel formed by the cutting mechanism, and aconnection between `the rear bearing and the said frame adapted topermit relative pivotal movement about an axis perpendicular to the saidparallel bars, substantially as set forth.

6. In a tunneling machine, the combination of a rotary cuttingmechanism, a rotary shaft on which the cutting mechanism is mounted, twoshaft bearings with respect to one of which the shaft is longitudinallymovable each bearing having a non-rotary part, a sup orting frame forone of the bearings, said rame being provided with means for engagingthe tunnel walls at opposite points, and means whereby the bearing may.

be` moved bodily relatively to both ofthe points of support of theframe, substantially as set forth.

.7. In a tunneling machine, the combination of a rotary cutting devicecomprising a main cutting mechanism, a supplementaryr cutting mechanismin advance thereof and adapted to cut an opening in the forward I faceof the tunnel, and a bearing for. the

cutting deviceV adapted to enter the opening, the said bearingcomprising a rotary support for the cutting device, a non-rotary sleevesurrounding said support and adapted to engage the walls of the saidopening, and rollers between the said rotary support and the non-rotarysleeve, forth.

u 8. In a tunneling machine, the combination of a rotary cutter head, acutting mechanism rigidly connected thereto and adapted to cut. theforward face of the tunnel, and a reciprocatory tool on the cutter headadapted to strike a wall of the tunnel at an acute angle relative to thewall and to the line of rotary movement of the tool to rotate the cutterhead`and actuate the cutting mechanism connected thereto, substan-`tially as set forth. l

9. In a tunneling machine, the combination of a rotary cutter head, anda plurality of cutting devices connected to said head. some of saiddevices being rigidly attached and others being reciprocatory toolsadapted to strike the forward face at backward acute angles relative tothe lines of rotary movement of the tools to rotate the cutter head andactuate the other cutting device, substantially as set forth.

10. VIn a tunneling machine, the combination of a rotary cuttingmechanism comprising a plurality of reciprocatory tools adapted tooperate at angles to the axis of the mechanism and to the lines ofrotary movement of the tools, `a second cutting mechanism adapted to cutan opening in the forward face of the tunnel, and a support for the'first cutting mechanism adapted to enter the said opening and engage thewalls thereof, substantially as set forth.

11. In a tunneling machine, the combination of a rotary cutterl head, acutting mechanism attached thereto, and reciprocatory tools arranged tostrike the cylindrical wall of the tunnel at a backward acute anglerelative to the lines of rotary movement of the tools to rotate thecutter head and the attached cutting mechanism, substantially as setforth.

12. In a tunneling machine, the combination of a rotary cutter head, acutting mechanism attached thereto, and devices arranged to engage thecylindrical wall of the tunnel to rotate the cutter head and theattached cutting mechanism, substantially as set forth.

substantially as set' 13. In a tunneling machine, the combination of arotary cutter head, reciprocatory cutters adjustably mounted on thecutter Ihead and each adapted to strike the forward face of the tunnelat any one of a plurality of backward acute angles relative to the linesof rotary movement of the cutters to rotate the cutter head, andsupplementary means connected to the cutter head and adapted to engageand push against the cylindrical wall of the tunnel to aid the rotationof the cutter head, substantially as set forth.

14. In a tunneling machine, the combination of a rotary rock cutting andbreaking mechanism, constructed and arranged to act upon the entire areaof the forward face of the tunnel and means foradjusting the cutting andbreaking mechanism to cut tunnels ofdiiferent diameters, substantiallyas set forth.

15. In a tunneling machine, the combination of a rotary cutter headcomprising a plurality of radial arms, each arm having a radiallyadjustable section, and cutters mounted upon the adjustable sections ofthe .said arms.

16. In a tunneling machine, the combination of a rotary cutter headcomprising a plurality of radial arms, each arm having an adjustablesection, and a plurality of cutters mounted upon the said arms, some ofsaid cutters being on'the adjustable sections and some on the fixedparts. of the arms, substantially as set forth.

17. ,In a tunneling machine, a rotary cutting device comprising meansfor cutting a central opening in the forward face, a nonrotary supportarranged to enter the opening and engage the walls thereof, means forcutting an annular groove in the forward face at its circumference, andmeans for cutting an annular groove in the forward face between thecentral opening and the circumferential groove, substantially vas setforth.

18. In a tunneling machine, the combination of a rotary cutter head, acutting device connected to the head for cutting a central opening inthe forward face of the tunnel, a support arranged to enter the centralopening and engage the walls thereof, cutting de- `vic`es for cutting aplurality of annular grooves concentric with the central opening, andmeans operating automatically and-simultaneously with the centralcutting device and the groove cutting devices for breaking down thematerial between the grooves and v between the inner groove and thecentral opening, substantially as set forth. j

19. In a tunneling machine, the combination of a rotary cuttingmechanism comprising a plurality of reciprocatory tools for cutting aplurality of substantially separated annular grooves in the forward faceof the tunnel, the said tools being arranged to operrasa-,eee

ate at backward acute angles relative to the forward face and to theirlines of rotary movement, and reciprocatory devices for breaking downthe material between the grooves, the said devices operating in a planebehind the bottoms of the grooves and at backward acute angles to theface of thetunnel and to the lines of rotary movement of the devices,substantially as set forth.

20. In a tunneling machine, the combination of a rotary mechanismcomprising a plurality of reciprocatory rock engaging tools arranged intwo groups, those of one group being arranged to cut a plurality ofsubstantiallyv separated annular grooves in the forward face of thetunnel and those of the other group being arranged to operatesimultaneously with those of the first group in aplane behind thebottoms of the grooves to break the material between the grooves, andmeans whereby each of the tools may beindependently adjusted to engagethe forward face of the tunnel at any one of a plurality of angles withrespect to its line of rotary movement, substantially as set forth.

21. In a tunneling machine, the combination of a rotary mechanismcomprising a plurality of reciprocatory -rock engaging tools arranged intwo groups, those of one group being arranged to cut a plurality ofsubstantially separated annular grooves in the forward face of thetunnel and those of they other group being arranged to operatesimultaneously with those of the first group in a plane behind thebottoms of the grooves to break the material between the grooves, andmeans whereby the tools of one group may be adjusted to strike the faceof the tunnel at diiferent angles with respect to the lines of rotarymovement from the tools of the other group, substantially as set forth.

22. In a tunneling machine, the combination of a forward cuttingmechanism adapted to form an opening, a conveyer adapted to carrymaterial backward from the cutting mechanism, a second cutting mechanismbehind the first cutting mechanism and adapted to cut a larger openingconcentric with the first openin a conveyer behind the second cuttingmec anism, and a scoop ,for elevating debris discharged from the firstconveyer and the second cutting mechanism and delivering it to thesecond conveyer, substantially as set forth. l

23. In a tunneling machine, the combination of a linearly moving cuttingmechanism, a support in advance of the cutting mechanism and adapted tomove therewith, a stationary support behind the cutting mechanism andarranged to permit adjustment of the cutting mechanism about atransverse axis and about a vertical axis and means connected to thesaid stationary support for linearly feeding the cutting mechanism,substantially as set forth.

24. In a tunneling machine, the combinaforce to be applied to thecutting mechanism, 10 tion of a linearly movable rotary cuttingsubstantially as set forth.

mechanism, a support in advance of the cut- In testimony whereof I ax mysignature tlng mechanism and adapted to move therein presence of twoWitnesses.

with a stationary support ehind'the cutting f meclianism, meansconnected to the said sta- EDWARD S' MCKINLA tionary support forlinearly feeding the cut- Witnesses:

ting mechanism', and means for engaging the E. L. PRENTLss,

cyllndrical tunnel Wall to cause rotative J. H. PFUSCH.

